煤沥青中间相热聚合行为研究

Study on the Behavior of Mesophase Development of Coal-tar pitch During Thermal Polymerization

以煤沥青为原料,采用程序升温、多管井式坩埚炉进行热转化反应,研究不同结构反应器中中间相的热聚合行为。试验显示:煤沥青中间相的光学结构与均相成核的中间相沥青相似;另一方面,热转化过程中不同结构反应器内样品的中间相生长存在差异。随着反应时间的延长,样品收率、挥发份产率不断降低,而软化点和甲苯不溶物含量则不断升高。对于不同结构的反应器,等径管内热反应样品的收率、挥发份产率比变径管内样品的偏低,甲苯不溶物含量和软化点则偏高;同时光学结构显示,等径管内中间相球体生成、长大、融并到变形的速率比变径管内样品快。分析认为:由于变径管中段直径的改变,对底端样品中的轻组分产生了中段截流作用,致使热聚合反应程度不同。

Using coal-tar pitches as raw material, the thermal conversion experiments were done in multi-tube well- crucible controlled by programmed heating. The purpose of this study was to study the behavior of thermal polymerization of mesophase during experiments in two different types of reactors. The results showed that the optical structures of the mesophase from coal-tar pitches were identical with that of the mesophase pitches of the homophase, but the growth of the meso differeed in the two style reactors during thermal conversion reaction. The sample yield and the fugitive constituent decreased with time, but the softening point and the content of toluene insoluble components increased. For these two style reactors the sample yield and the fugitive constituent were lower in reactors with single diameter than in that with two diameters. Meanwhile, the softening point and the content of toluene insoluble components ehanged oppositely. In addition ,as showed in micrographs, the speed of nucleation, growth ,coalescence and distortion of mesophase spheres was faster in reactors with single diameter than in those with two diameters. Due to the different diameter in the middle part of the tube, most light components were blocked in the bottom part of the tube, accordingly thermal polymerization was inhibited.